s390/vfio-ap: manage link between queue struct and matrix mdev
Let's create links between each queue device bound to the vfio_ap device
driver and the matrix mdev to which the queue's APQN is assigned. The idea
is to facilitate efficient retrieval of the objects representing the queue
devices and matrix mdevs as well as to verify that a queue assigned to
a matrix mdev is bound to the driver.
The links will be created as follows:
* When the queue device is probed, if its APQN is assigned to a matrix
mdev, the structures representing the queue device and the matrix mdev
will be linked.
* When an adapter or domain is assigned to a matrix mdev, for each new
APQN assigned that references a queue device bound to the vfio_ap
device driver, the structures representing the queue device and the
matrix mdev will be linked.
The links will be removed as follows:
* When the queue device is removed, if its APQN is assigned to a matrix
mdev, the link from the structure representing the matrix mdev to the
structure representing the queue will be removed. Since the storage
allocated for the vfio_ap_queue will be freed, there is no need to
remove the link to the matrix_mdev to which the queue's APQN is
assigned.
* When an adapter or domain is unassigned from a matrix mdev, for each
APQN unassigned that references a queue device bound to the vfio_ap
device driver, the structures representing the queue device and the
matrix mdev will be unlinked.
* When an mdev is removed, the link from any queues assigned to the mdev
to the mdev will be removed.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>